Question

thực hiện phép tính sau :

a)\(3^3+ 3\)\((-1/2)^3 \)- 0,75

b) (3/15- 12/16+7/14) nhân với cái số trong hình nha.

Answer 1

Ta có:

\(\left(\frac{3}{15}-\frac{12}{16}-\frac{7}{14}\right)\cdot\left(-1\frac{5}{14}\right)\)

\(=\left(\frac{1}{5}-\frac{3}{4}-\frac{1}{2}\right)\cdot\left(-\frac{19}{14}\right)\)

\(=\left(\frac{4}{20}-\frac{15}{20}-\frac{10}{20}\right)\cdot\left(-\frac{19}{14}\right)\)

\(=\left(-\frac{21}{20}\right)\cdot\left(-\frac{19}{14}\right)\)

\(=\frac{57}{40}\)

Answer 2

a) Ta có:

\(3^3+3\cdot\left(-\frac{1}{2}\right)^3-0,75\)

\(=27+3\cdot\left(-\frac{1}{8}\right)-\frac{3}{4}\)

\(=27+\left(-\frac{3}{8}\right)-\frac{6}{8}\)

\(=27+\left[\left(-\frac{3}{8}\right)+\left(-\frac{6}{8}\right)\right]\)

\(=27+\left(-\frac{9}{8}\right)\)

\(=\frac{207}{8}\)